1. Field of the Invention
The subject invention relates generally to active rectification, and more particularly, to a method of reducing input current distortion in a three-level Vienna-type active rectifier used in aerospace applications.
2. Description of Related Art
It has been determined that uni-directional active rectifiers, also known as a Vienna-type active rectifiers, are good candidates for use in aerospace applications in which there is a need to convert AC input voltage sources into dual DC-bus voltage. The dual DC-bus voltage can then be used to efficiently drive DC-AC three-level power converters/inverters such as, for example, the motor drive systems and battery charging systems employed on aircraft.
It has also been determined that harmonic distortion in the input currents to a Vienna-type active rectifier can exceed the power quality specifications for certain aerospace applications. This can occur at an input frequency range from 360 Hz up to 800 Hz (as in currently used aircraft CF and VF power systems).
It would be beneficial therefore, to minimize input current harmonic distortion in a Vienna-type active rectifier in order to achieve better power quality, and thereby meet the specifications for a given application.